Double clutch

ABSTRACT

A double clutch for a double clutch transmission in the drive train of a motor vehicle, with single clutches that are arranged behind each other in the axial dimension and actuated hydraulically, including a single clutch arranged on the drive side, a single clutch arranged on the gear side, a driven clutch housing and two piston-cylinder units. The first of the two single clutches connects the clutch housing to the first transmission input shaft and the second single clutch connects the clutch housing to a second transmission input shaft, wherein both connections can be switched. The clutch housing is connected on the drive side to a drive shaft and on the gear side to input disk carriers.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent claims priority from German Patent Application No. 10 2010 047 426.6, filed Oct. 6, 2010, which application is incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

This invention relates to a double clutch having single clutches, arranged axially behind each other and actuated hydraulically, for a double clutch transmission in a drive train of a vehicle, having a single clutch arranged on the drive side, a single clutch arranged on the gear side, a driven clutch housing, and two piston-cylinder units, whereby a first single clutch switchably connects the clutch housing to a first transmission input shaft and a second single clutch connects the clutch housing to a second transmission input shaft.

BACKGROUND OF THE INVENTION

Such a hydraulically actuated (actuatable) double clutch with single clutches arranged behind each other in the axial dimension is disclosed in DE 38 19 702 A1. In this case, the hydraulic actuating devices are arranged in front of and/or behind the single clutches in the axial dimension and on the same diameter as the single clutches. The installation space requirements in the axial dimension for this wet double clutch are therefore comparatively large. In order to reduce the installation space requirements in the axial dimension, the hydraulic actuating devices could be displaced inward radially and optionally arranged overlapping with the single clutches in the axial dimension, as per DE 2 191 252, DE 9 114 528, DE 38 38 865, DE 2 116 311, or DE 35 27 399. An even more compact construction could be achieved by providing a common clutch rod that is rigidly connected to the clutch housing and arranged between the two single clutches and the two piston-cylinder units. This arrangement is per U.S. Pat. No. 3,424,033 or EP 1 195 537. In the case of the construction as per these two publications, however, the common rod results in cross-talk between the single clutches, due to the fact that the shifting forces of the single clutches share a common support via the clutch rod.

BRIEF SUMMARY OF THE INVENTION

This invention relates to a double clutch for a double clutch transmission in the drive train of a motor vehicle, with single clutches that are arranged behind each other in the axial dimension and actuated hydraulically. It has a single clutch arranged on the drive side, a single clutch arranged on the gear side, a driven clutch housing and two piston-cylinder units. The first of the two single clutches connects the clutch housing to the first transmission input shaft and the second single clutch connects the clutch housing to a second transmission input shaft, wherein both connections can be switched. The clutch housing is connected on the drive side to a drive shaft and on the gear side to input disk carriers. An input torque transmitted into the double clutch can be transmitted via the clutch housing around both single clutches, wherein the clutch housing has a primary support area for an actuating force of the single clutch arranged on the gear side and a secondary support that is independent of the primary support area, which serves to support an actuating force of the single clutch arranged on the drive side.

For this reason, the object of the present invention is to provide an axially-oriented double clutch that avoids and/or substantially reduces cross-talk between the single clutches, and which has comparatively small spatial requirements.

The invention attains the present object regarding a double clutch of the type named above in that the clutch housing is connected on the drive side to a drive shaft and on the gear side to input disk carriers. An input torque transmitted into the double clutch can be directed via the clutch housing around the two single clutches, whereby the clutch housing has a first support area for an actuating force of the single clutch arranged on the gear side, and whereby a second support area that is independent of the first support area, is provided to support an actuating force of the single clutch arranged on the drive side.

The invention, therefore, provides a double clutch, wherein it is arranged in the axial dimension, and the input torque is transmitted via the clutch housing arranged on the outside around the individual clutches to drive the disk carrier arranged inside. In this case, the housing arranged on the outside simultaneously functions to separately support the axial actuating force of one of the individual clutches. The axial actuating force of the corresponding second individual clutch in this case is received via an additional support element. By means of this separate support of the actuating forces, cross-talk between the two individual clutches is prevented. At the same time, the construction is extremely compact and requires accordingly less installation space.

In this case, the clutch housing preferably has an engaging region arranged substantially radially with respect to a primary axis of the double clutch and connectable to the drive shaft, a cylindrical region arranged substantially axially with respect to the primary axis of the double clutch, and a connection and support region arranged substantially radially with respect to a primary axis of the double clutch.

In addition, the clutch housing is connected to a clutch hub, wherein the clutch hub can be connected to the input disk carriers of both single clutches. In this case, the clutch housing is preferably connected to the clutch hub via an axial splining or by another connection that also transmits rotation (such as a feather key connection), whereby the axial splining, or the other rotation-transmitting connection with the same function, is arranged on the gear side.

In a preferred embodiment, both piston-cylinder units each have an actuating piston and a seal support, which, along with a sub-region of the clutch hub outer surface, form a separate actuating compartment, whereby the actuating pistons are each preloaded via a spring element, which itself is supported on the corresponding support element and/or on the connection and support region of the clutch housing, and/or is supported directly on the input disk carrier. In an alternative embodiment, the piston-cylinder units each comprise an actuating piston and a common seal support, which, along with a sub-region of the clutch hub outer surface, form a separate actuating compartment for the single piston-cylinder units whereby the actuating pistons in this case are preloaded via a spring element that is supported on the support element and/or on the connection and support region of the clutch housing. In both of these alternative embodiments, the actuating pressure compartments and the spring elements can each be arranged radially inside the input disk carrier of the associated single clutch.

According to another embodiment, a support element is provided connected non-rotatably to the clutch hub, for the purpose of supporting the actuating forces of the single clutch arranged on the drive side such that the actuating forces of the single clutches are supported separately and thereby cross-talk between the two single clutches can be prevented.

Output disk carriers are preferably provided that are nested in each other and arranged radially on the outside with respect to the input disk carriers. In this case, the input disk carriers mentioned above can also be designed as sub-areas of a common input disk carrier.

In a preferred embodiment, the contact regions of the actuating pistons on each disk packet of both single clutches are each arranged on the drive side of the respective single clutch, such that an actuating direction of both single clutches extends in the direction of the gearing. In an alternative embodiment, the contact areas of the actuating pistons on each disk packet of the single clutches are each arranged between the two single clutches, such that an actuating direction of the drive-side clutch extends in the direction of the drive, and the actuating direction of the gear-side single clutch extends in the direction of the gearing. In another alternative embodiment, the contact areas of the actuating pistons on the disk packets of each single clutch are each arranged on the gear side of the respective single clutch, such that the actuating direction of both of the single clutches extends in the direction of the gearing, and in this way two separate support elements are provided for the single clutches, in such a way that there is no direct support on the clutch housing.

BRIEF DESCRIPTION OF THE DRAWINGS

This invention is described in greater detail below using preferred embodiments, with reference to the associated figures, wherein:

FIG. 1 shows a basic arrangement of the double clutch according to the invention;

FIG. 2 shows a first embodiment with the actuating direction of both single clutches extending toward the gearing; and,

FIG. 3 shows another embodiment with the actuating direction of both single clutches extending in the opposite direction.

DETAILED DESCRIPTION OF THE INVENTION

Here, FIG. 1 is a schematic illustration of the drive train of a vehicle, with a drive 1, a double clutch transmission 2, and a double clutch device 3 arranged between the drive 1 and the double clutch transmission 2. In this case, the torque generated by the drive 1 (preferably an internal combustion engine or an electric drive, or a combination of internal combustion engine and electric drive) is transmitted around the double clutch arrangement 3 via the clutch housing 4 to a clutch hub 5. The clutch hub 5 is connected to an input disk carrier 6 of the first single clutch K1 and to an input disk carrier 7 of a second single clutch K2. The single clutches K1 and K2 have disk packets (which are not shown individually in FIG. 1) that each consist of at least one input side friction disk and one output side friction disk. The output side friction disks are connected to an output side disk carrier 8 for the single clutch K1 and an output disk carrier 9 for the single clutch K2. The input side and output side friction disks can be brought into friction—contact with each other via the actuating devices 10 and 11, wherein the actuating force in each case, and the direction of the actuating force, are indicated by the force vector arrows F_(K1) and F_(K2) for the single clutches K1 and K2 in FIG. 1. The output disk carriers 8 and 9 are connected to both of the transmission input shafts 12 and 13 of the double clutch transmission. In FIG. 1, the primary axis of the double clutch arrangement 3 is indicated by reference letter A.

In addition, the sub-area 4 a of the clutch housing is symbolically emphasized in

FIG. 1 to illustrate that, in the case of a wet double clutch mechanism with partial clutches (single clutches) arranged in the axial dimension, the actuating force of the partial clutch K1 is supported via a component that also simultaneously transmits the drive torque into the clutch system. The clutch housing therefore fulfills two functions in this case.

In addition, the figure attempts to clarify, by likewise symbolically emphasizing area 14, that support of the actuating force of the partial clutch K2 occurs via the additional component 14, which is substantially independent from the support 4 a on the clutch housing 4. This configuration prevents the partial clutches K1 and K2 from mutually influencing each other (creating cross-talk) upon their actuation.

In this case, the partial clutches could be actuated in the direction extending toward the gearing or the direction extending toward the drive (even though this is not indicated in the figures).

An arrangement could also be contemplated wherein the partial clutches K1 and K2 are actuated from the inside out, as is explained below with reference to FIG. 3. In this case, the actuating elements of the partial clutches are then situated between the disk packets in the axial dimension. If actuation occurs in the opposite direction, it is also possible to form the pressure compartments of the actuating elements by means of a common seal support that supports the piston seal for each partial clutch.

In this case, the schematic illustration in FIG. 1 shows that the clutch housing 4 can be designed as a clutch pot with a support, designed as an integral component thereof, for supporting the axial actuating force.

In addition, the schematic illustration in FIG. 1 shows that the input disk carriers situated inside are connected to the clutch hub.

Furthermore, the schematic illustration in FIG. 1 demonstrates that the additional support element 14 can also be connected to the clutch hub.

FIG. 2 shows a detailed construction wherein the actuating forces correspond to the force vectors F_(K1) and F_(K2) illustrated in FIG. 1. In this case, FIG. 2 shows a half section corresponding to the clutch primary axis A. The clutch housing 4 in this case is designed in two parts, consisting of a clutch pot with the base region 4 a and the cylindrical wall region 4 b, and a dog plate 4 c. The dog plate 4 c and the cylindrical wall area 4 b are connected to each other in a non-rotatable and positive fit connection and secured in the axial dimension via a retaining ring 15.

The base region 4 a, which also serves to support the axial actuating force of the clutch K1, is rigidly connected to an output component 16. A pump for moving hydraulic fluid can be driven via said output component 16. Accordingly, the latter 16 has a toothing 16 a for transmitting torque to a hydraulic pump. The component 16 also has an axial toothing which faces inward, for the purpose of connecting to a clutch hub 17. The axial splining provided between the component 16 and the clutch hub 17 could also be replaced by a feather key connection or another connection that transmits torque. This axial splining or similar connection in this case is secured via a retaining ring or by a similar securement device, for example a shaft nut 18.

FIG. 2 also shows the input disk carrier 6 of the partial clutch K1, wherein the input disk carrier 6 in this case is connected to the component 16, such that torque is directly transmitted via this component 16. As an alternative, the input disk carrier 6 could also be arranged on the clutch hub 17.

FIG. 2 also shows the input disk carrier 7 of the partial clutch K2, where the input disk carrier 7 is directly bonded to the clutch hub 17. The additional support component 14 is arranged between the input disk carrier 7 of the partial clutch K2 and a projection on the clutch hub 17. In this case, it is sufficient that the additional component 14 is supported against the clutch hub 17, against rotation and against displacement in the direction of the gearing. In this case, it is not absolutely necessary for the additional component 14 to be additionally fixed in the axial dimension in the direction of the drive. The support component 14 and the input disk carrier 7 could also be designed as integral components.

In addition, sealing plates 19 and 20 are arranged on the clutch hub 17 and function as seal supports for both of the hydraulic piston-cylinder units, which actuate the partial clutches K1 and K2. The pressure compartments 23 and 24 are formed between the sealing plates 19 and 20 and the actuating pistons 21 and 22 of the partial clutch K1 and K2 and corresponding partial areas of the outer surface of the clutch hub 17. These pressure compartments 23 and 24 are supplied with hydraulic fluid via the clutch hub 17 as well as an oil supply and support component 25 that is situated on the inside. At least two radial bearings 26 and 27, as well as multiple sealing elements, are arranged between this support component 25 situated on the inside and the clutch hub 17.

In this case, the actuating pistons 21 and 22 are preloaded in the “clutch open” direction via spring elements 28 and 29 (wherein it can certainly also be contemplated to include a preloading in the “clutch closed” direction of at least one of the clutches, whereby energetic advantages would result). The spring elements 28 and 29, designed as coils springs in this case, are each supported on a support component 30 and 31. The components 30 and 31 are supported in the axial dimension on corresponding input disk carriers 6 and/or 7.

The torque that can be transmitted via the disk packets of the partial clutches K1 and K2 upon the exertion of a corresponding actuating force is transmitted via the output disk carriers 32 and 32 to the transmission input shaft, which is not shown in detail in FIG. 2. In this case, the transmission input shafts are designed as a solid shaft and a hollow shaft that are arranged concentrically to each other.

In the embodiment shown in FIG. 2, an actuating force is applied to the single clutches—that is, in the direction of the gearing in both cases—wherein the actuating force of the gear side partial clutch K1 is transmitted to the clutch pot and the actuating force of the drive side partial clutch K2 is transmitted to a separate support element. The support element 14 does not form a component of the piston-cylinder unit of the associated single clutch, and, optionally, could be designed as an integral component of the input disk carrier 7.

The clutch shown in FIG. 2, connected to the securement element 18, is braced in the axial dimension via axial bearings between the dog plate 4 c and output disk carrier 32, as well as between the output disk carrier 32 and the output disk carrier 33, as well as between the output disk carrier 33 and the front end of the clutch hub 17. In addition, the component 25 situated on the inside is either supported via one of the transmission input shafts, or via a connection to the clutch bell.

Another embodiment of the double clutch is shown in FIG. 3. Essentially, only the differences from the embodiments described above will be described below. Components that are the same as above are indicated by the same reference numbers.

The double clutch, as per the embodiment according to FIG. 3, has a clutch housing 4′ wherein the dog plate has been arranged on the gear side and the clutch pot has been arranged on the drive side—that is, the mirror image configuration of the clutch housing consisting of dog plate and clutch pot is provided in this case. In this mirror-image arrangement, the support area of the actuating force of the partial clutch K1 arranged on the gear side is therefore constructed on the dog plate 4 c rather than in the base region 4 a.

According to the embodiment as it appears in FIG. 3, the input disk carrier is also modified, only in that it has a disk receiving area 6 a′, which is connected to the dog plate 4 c′, such that the dog plate 4 c′ also supports the disk receiving area 6 a′ on the clutch hub 17′. As an alternative to this example of an integral design of the dog plate and the input disk carrier, an input disk carrier could also be used according to the embodiment appearing in FIG. 2, wherein the input disk carrier and the dog plate would then have an independent area extending radially for the purpose of connecting to the clutch hub 17, with an optional pump output area inserted between, wherein the latter is comparable to the component 16 in FIG. 2.

In addition, a support plate 14′ is arranged on the clutch hub 17 and also forms the support area of the input disk carrier 7 of the partial clutch K2. Therefore, in this case, once again, only one disk holder area 7 a′ is necessary, wherein it is connected to the support plate 14′.

As an alternative to this configuration, an input disk carrier according to the embodiment according to FIG. 2 could also be provided separately from the support plate 14′.

The actuating force is transmitted via the actuating pistons 21 and 22 to the disk packets of the partial clutches K1 and K2, wherein the actuating pistons 21 and 22 with a common seal support 34 (which in this case replaces the separate sealing plates 21 and 22 in FIG. 2) form the pressure compartment 23 and 24 along with sub-regions of the outer surface of the clutch hub 17′.

The actuating pistons 21 and 22 are arranged between the single clutches K1 and K2 in the axial dimension according to the embodiment according to FIG. 3 and work in opposite directions, such that according to the embodiment as it appears in FIG. 3, the actuating force of the gear side partial clutch K1 works in the direction of the gearing and the actuating force of the partial clutch K1 arranged on the drive side works in the direction of the drive. The common seal support 34 is designed in this case as a separate component that is connected to the clutch hub 17′. A seal element is provided in order to seal the pressure compartments 23 and 24 with respect to each other.

The remaining features of this embodiment according to FIG. 3 correspond to those shown in the context of FIG. 1 and in the context of FIG. 2.

The embodiment shown in FIG. 2 therefore shows the actuating of both partial clutches in the direction toward the gearing. As an alternative, it is also possible for both partial clutches to be actuated in the direction of the engine. If actuation occurs in the direction of the gearing, the actuating force of the gear side partial clutch exerted in the axial dimension is supported via the base region of the clutch pot. If actuation of both partial clutches occurs in this direction, such a support would occur not on the clutch pot but rather on an additional support element, or, optionally, also directly on one of the output disk carriers.

According to the embodiment as it appears in FIG. 3, both partial clutches are actuated in the opposite direction, and the actuating pistons are situated between both of the partial clutches in the axial dimension. In this case, both actuating pressure compartments can be formed by a common seal support.

The embodiments according to FIGS. 1 to 3 therefore have in common that the drive of the double clutch device and the support of the actuating forces of one of the partial clutches occur via the drive pot and that the actuating force of the corresponding second partial clutch occurs via a separate component. In this way, the configuration prevents cross-talk between the partial clutches. Thus, actuation can occur in the direction of the gearing and/or in the direction of the engine. Accordingly, it is possible to actuate the partial clutches “from the inside out”—that is, according to the construction according to FIG. 3—wherein the partial clutch K1 is actuated in the direction of the gearing and the partial clutch K2 is actuated in the direction of the engine. Also, the actuating pistons are arranged between the two partial clutches in the axial dimension. In the event that the actuation of the partial clutches accordingly occurs “from the inside out,” the actuating pressure compartments of the partial clutches can be formed by a common seal support. This enables further integration of the components. 

1. A double clutch having single clutches, arranged axially behind each other and actuated hydraulically, for a double clutch transmission in a drive train of a vehicle, having a single clutch arranged on the drive side, a single clutch arranged on the gear side, a driven clutch housing, and two piston-cylinder units, whereby a first single clutch switchably connects the clutch housing to a first transmission input shaft and a second single clutch connects the clutch housing to a second transmission input shaft, wherein the clutch housing is connected on the drive side to a drive shaft and on the gear side to input disk carriers that are arranged on the inside with respect to the single clutches and an input torque transmitted into the double clutch can be transmitted via the clutch housing around the two single clutches, whereby the clutch housing has a first support area for an actuating force of the single clutch arranged on the gear side, and whereby a second support area that is independent from the first support area is provided to support an actuating force of the single clutch arranged on the drive side.
 2. The double clutch recited in claim 1 wherein the clutch housing has an engaging region arranged substantially radially with respect to a primary axis of the double clutch and connectable to the drive shaft, a cylindrical region arranged substantially axially with respect to the primary axis of the double clutch, and a connection and support region arranged substantially radially with respect to a primary axis of the double clutch.
 3. The double clutch recited in claim 1 wherein the clutch housing is connected to a clutch hub and the clutch hub is connected to the input disk carrier of the single clutches.
 4. The double clutch recited in claim 3 wherein the clutch housing is connected to the clutch hub via an axial splining, whereby the axial splining is arranged on the gear side.
 5. The double clutch recited in claim 1 wherein the piston-cylinder units each have an actuating piston and a seal support, which along with a sub-region of the clutch hub outer surface form a separate actuating pressure compartment, whereby the actuating pistons are each preloaded via a spring element that is supported on the corresponding support element and/or on the connection and support region of the clutch housing.
 6. The double clutch recited in claim 1 wherein the piston-cylinder units each have an actuating piston and a common seal support, which along with a sub-region of the clutch hub outer surface form a separate actuating pressure compartment, whereby the actuating pistons are each preloaded via a spring element that is supported on the support element and/or on the connection and support region of the clutch housing.
 7. The double clutch recited in claim 5 wherein the actuating pressure compartments and the spring elements are each arranged radially inside the input disk carriers of the associated single clutch.
 8. The double clutch according to claim 1 further comprising a support element, connected non-rotatably to the clutch hub, for the purpose of supporting the actuating forces of the single clutch arranged on the drive side, such that the actuating forces of the single clutches are supported separately and thereby cross-talk between the two single clutches can be prevented.
 9. The double clutch recited in claim 1 further comprising output disk carriers that are nested in each other and arranged radially on the outside with respect to the input disk carriers.
 10. The double clutch recited in claim 1 wherein the contact areas of the actuating pistons on each disk packet of the single clutches are each arranged on the drive side of the respective single clutch, such that an actuating direction of both single clutches extends in the direction of the gearing.
 11. The double clutch recited in claim 1 wherein the contact areas of the actuating pistons on each disk packet of the single clutches are each arranged between the two single clutches, such that the actuating direction of the drive side single clutch extends in the direction of the drive and the actuating direction of the gear side single clutch in the direction of the gearing. 